Urinary and faecal N-methylhistamine concentrations do not serve as markers for mast cell activation or clinical disease activity in dogs with chronic enteropathies

Background

This study sought to correlate faecal and urinary N-methylhistamine (NMH) concentrations with resting versus degranulated duodenal mast cell numbers in dogs with chronic enteropathies (CE), and investigate correlations between intestinal mast cell activation and clinical severity of disease as assessed by canine chronic enteropathy clinical activity index (CCECAI), and between urinary and faecal NMH concentrations, mast cell numbers, and histopathological scores. Twenty-eight dogs with CE were included. Duodenal biopsies were stained with haematoxylin and eosin (H&E), toluidine blue, and by immunohistochemical labelling for tryptase. Duodenal biopsies were assigned a histopathological severity score, and duodenal mast cell numbers were counted in five high-power fields after metachromatic and immunohistochemical staining. Faecal and urinary NMH concentrations were measured by gas chromatography–mass spectrometry.

Results

There was no correlation between the CCECAI and faecal or urinary NMH concentrations, mast cell numbers, or histopathological score – or between faecal or urinary NMH concentration and mast cell numbers. Post hoc analysis revealed a statistically significant difference in toluidine blue positive mast cells between two treatment groups (exclusion diet with/without metronidazole versus immunosuppression (IS)), with higher numbers among dogs not requiring IS.

Conclusion

Faecal and urinary NMH concentrations and duodenal mast cell numbers were not useful indicators of severity of disease as assessed by the CCECAI or histological evaluation. The number of duodenal mast cells was higher in dogs that did not need IS, i.e. in dogs responding to an exclusion diet (with/without metronidazole), than in dogs requiring IS. Further studies comparing the role of mast cells in dogs with different forms of CE are needed.     

Genome-wide association analysis identifies loci for type 2 diabetes and triglyceride levels

New strategies for prevention and treatment of type 2 diabetes (T2D) require improved insight into disease etiology. We analyzed 386,731 common single-nucleotide polymorphisms (SNPs) in 1464 patients with T2D and 1467 matched controls, each characterized for measures of glucose metabolism, lipids, obesity, and blood pressure. With collaborators (FUSION and WTCCC/UKT2D), we identified and confirmed three loci associated with T2D-in a noncoding region near CDKN2A and CDKN2B, in an intron of IGF2BP2, and an intron of CDKAL1-and replicated associations near HHEX and in SLC30A8 found by a recent whole-genome association study. We identified and confirmed association of a SNP in an intron of glucokinase regulatory protein (GCKR) with serum triglycerides. The discovery of associated variants in unsuspected genes and outside coding regions illustrates the ability of genome-wide association studies to provide potentially important clues to the pathogenesis of common diseases.     

Identification of parents suitable for molecular mapping of immunity and resistance genes in solanum species

A survey of DNA polymorphisms and bacterial ring rot reactions inSolanum species was conducted to identify parents that when crossed would produce an F₁ mapping population useful for identifying DNA markers tightly linked to genes for immunity or resistance to bacterial ring rot.Solanum tuberosum, S. acaule, diploidSolanum species, doubled monoploid lines ofS. phureja, and somatic fusion hybrids betweenS. tuberosum andS. brevidens were established in tissue culture from single true potato seeds or tubers and evaluated for bacterial ring rot reactions in greenhouse studies with root-inoculated tissue cultured plantlets. Establishment of tissue culture stocks insured the availability of homogeneous genetic material for use in bacterial ring rot assays and genetic analyses. Presence ofClavibacter michiganense subsp.sepedonicum was assessed in stems by an immunofluorescence antibody assay (IFAS). Two accessions were found to be immune to bacterial ring rot. DNA polymorphisms were detected within and among 24 accessions evaluated with 24 RFLP markers and 10 arbitrary oligonucleotide primers (RAPDs). These results identify parents suitable for future mapping of gene (s) for immunity or resistance to bacterial ring rot.     

Hepatic lobe torsion in a horse

A 4-year-old Belgian mare was presented with a 1-week history of fever, suspected of being caused by peritonitis. The mare died before the diagnostic procedures had been completed; postmortem examination revealed torsion of the left medial lobe of the liver, resulting in diffuse necrosis of liver tissue and severe peritoneal effusion.     

Descriptive report of antebrachial growth deformity correction in 17 dogs from 1999 to 2007, using hybrid linear-circular external fixator constructs

The radiographic and clinical results from 17 dogs (18 limbs) in which hybrid linear-circular external fixators (HLCEF) were used for the correction of antebrachial growth deformities (AGD) are described, retrospectively. Wedge ostectomy and the application of a type IA or IB HLCEF were performed in all cases. Pre- and postoperative AGD measurements, complications, time to staged destabilization and/or fixator removal, cosmesis, and limb function were evaluated. Complications included wire and/or pin tract inflammation (11 limbs) and radial fracture (2 limbs). All dogs had improved function and appearance after surgery. Limb function was assessed as excellent in 13 cases and good in 4 cases. Limb appearance was assessed as excellent in 12 cases and good in 5 cases. This case series substantiates the utility of HLCEF for the correction of AGD in dogs.